Chapter 7

1. Chapter 7  Radiologic Examination of the Chest

2. Fundamentals of Radiography

3. Standard Positions and Techniques of Chest Radiography • Posteroanterior (PA) radiograph • Anteroposterior (AP) radiograph • Lateral radiograph • Lateral decubitus radiograph

4. Posteroanterior Radiograph • The standard PA chest radiograph is obtained by having the patient stand (or sit) in the upright position. • The anterior aspect of the patient’s chest is pressed against a film cassette holder.

5. Figure 7-1. Standard PA chest radiograph with the patient’s lungs in full inspiration.

6. Figure 7-2. A PA chest radiograph of the same patient shown in Figure 7-1 during expiration.

7. Figure 7-3. Compared with the PA chest radiograph, the heart is significantly magnified in the AP chest radiograph. In the PA radiograph the ratio of the width of the heart to the thorax is normally less than 1 : 2.

8. Anteroposterior Radiograph • The supine AP radiograph may be taken in patients who are debilitated, immobilized, or too young to tolerate the PA procedure. • The AP radiograph is usually taken with a portable x-ray machine at the patient’s bedside. • The film is placed behind the patient’s back, with the x-ray machine positioned in front of the patient approximately 48 inches from the film.

9. Figure 7-4. AP chest radiograph. The diaphragms are elevated, the lower lung lobes appear hazy, the ratio of the width of the heart to the thorax is greater than 2 : 1, and extraneous lines are apparent on the patient’s left side.

10. Lateral Radiograph • The lateral radiograph is obtained to complement the PA radiograph. It is taken with the side of the patient’s chest compressed against the cassette. • The patient’s arms are raised, with the forearms resting on the head.

11. Figure 7-5. Lateral radiograph.

12. Lateral Decubitus Radiograph • The lateral decubitus radiograph is obtained by having the patient lie on the left or right side rather than standing or sitting in the upright position. • The naming of the decubitus radiograph is determined by the side on which the patient lies. • Thus a right lateral decubitus radiograph means that the patient’s right side is down.

13. Figure 7-6. Subpulmonic pleural effusion. Right lateral decubitus view. Subdiaphragmatic fluid has run up the lateral chest wall, producing a band of soft tissue density. The medial curvilinear shadow (arrows) indicates fluid in the lips of the major fissure.

14. Inspecting the Chest Radiograph

15. Figure 7-7. Normal PA chest radiograph. 1, Trachea (note vertebral column in middle of trachea);2, carina; 3, right main stem bronchus; 4, left main stem bronchus; 5, right atrium; 6, left ventricle; 7, hilar vasculature; 8, aortic knob; 9, diaphragm; 10, costophrenic angles; 11, breast shadows;12, gastric air bubble; 13, clavicle; 14, rib.

16. Figure 7-8. Normal lateral chest radiograph. 1, Manubrium; 2, sternum; 3, cardiac shadow;4, retrosternal air space in the lung; 5, trachea; 6, bronchus, on end; 7, aortic arch (ascending and descending); 8, scapulae; 9, vertebral column; 10, diaphragm; 11, breast shadow.

17. Table 7-1 Common Radiologic Terms • Air cyst • Bleb • Bulla • Bronchogram • Cavity • Consolidation • Homogeneous density • Honeycombing • Infiltrate

18. Table 7-1 Common Radiologic Terms (Cont’d) • Interstitial density • Lesion • Opacity • Pleural density • Pulmonary mass • Pulmonary nodule • Radiodensity • Radiolucency • Translucent

19. Selected Examples of Common Radiologic Terms

20. Cavity Lung abscess with cavities Radiograph of cavity Reactivation tuberculosis (TB) with a large cavitary lesion containing an air-fluid level in the right lower lobe. Lung abscess with air-fluid cavity.

21. Cavity (Cont’d) Lung with TB cavities Radiograph of cavity Tuberculosis. Cavitary reactivation TB showing a left upper lobe cavity and localized pleural thickening (arrows).

22. Consolidation or Opacity(Caused by Right Lung Pneumonia) Pneumonia

23. Bronchogram Air bronchogram.

24. BronchogramShown in Chest CT Scan

25. HoneycombingShown in Interstitial Pulmonary Fibrosis Honeycomb cysts.

26. InfiltrateShown in Patient with ARDS—General Term Cross-sectional view of alveoli in adult respiratory distress syndrome. Chest x-ray film of a patient with moderately severe ARDS.

27. Pleural Density Right-sided pleural effusion.

28. Pulmonary Mass Cancer of the lung. Cancer of the lung.

29. Radiodensity (Caused by a Right Lung Pneumonia) Pneumonia

30. Translucency or Radiolucency(Caused by a Right Pneumothorax) Right pneumothorax

31. Translucency or RadiolucencyCaused by Chronic Emphysema Centrilobular emphysema. Chest x-ray study of a patient with emphysema.

32. Technical Quality of the Radiograph • Technical quality • Exposure quality • Level of inspiration

33. FirstTechnical Quality • Was the patient in the correct position? • Check the medial ends of the clavicles to the vertebral column. • Even a small degree of patient rotation can create a false image. • Can erroneously suggest tracheal deviation, cardiac displacement, or cardiac enlargement

34. SecondExposure Quality • Normal exposure is verified by determining whether the spinal processes of the vertebrae are visible to the fifth or sixth thoracic level. • Compare the relative densities of the heart and lungs. • Overexposure: heart and lungs more radiolucent • Underexposure: heart and lungs more dense or whiter

35. Third Level of Inspiration When Radiograph Was Taken • At full inspiration, the diaphragmatic domes should be at the level of the ninth to eleventh ribs posteriorly. • At expiration, the lungs appear denser, the diaphragm is elevated, and the heart appears wider and enlarged.

36. Sequence of Examination • Mediastinum • Trachea • Heart • Hilar region • Lung parenchyma (tissue)

37. Figure 7-7. Normal PA chest radiograph. 1, Trachea (note vertebral column in middle of trachea);2, carina; 3, right main stem bronchus; 4, left main stem bronchus; 5, right atrium; 6, left ventricle; 7, hilar vasculature; 8, aortic knob; 9, diaphragm; 10, costophrenic angles; 11, breast shadows;12, gastric air bubble; 13, clavicle; 14, rib.

38. Sequence of Examination (Cont’d) • Pleura • Diaphragm • Gastric air bubble • Bony thorax • Extrathoracic soft tissues

39. Figure 7-7. Normal PA chest radiograph. 1, Trachea (note vertebral column in middle of trachea);2, carina; 3, right main stem bronchus; 4, left main stem bronchus; 5, right atrium; 6, left ventricle; 7, hilar vasculature; 8, aortic knob; 9, diaphragm; 10, costophrenic angles; 11, breast shadows;12, gastric air bubble; 13, clavicle; 14, rib.

40. Structure Mediastinum Trachea Carina Heart Major vessels Abnormal Position Leftward shift Table 7-2 Examples of Factors That Pull or Push Anatomic Structures out of Their Normal Position in the Chest Radiograph Causes • Pulled left by upper lobe tuberculosis, atelectasis, or fibrosis • Pushed left by right upper lobe emphysematous bulla, fluid, gas, or tumor

41. Structure Left diaphragm Abnormal Position Upward shift Table 7-2Examples of Factors That Pull or Push Anatomic Structures out of Their Normal Position in the Chest Radiograph (Cont’d) Causes • Pulled up by left lower lobe atelectasis or fibrosis • Pushed up by distended gastric air bubble

42. Structure Horizontal fissure Right lung Right hilum Abnormal Position Downward shift Table 7-2Examples of Factors That Pull or Push Anatomic Structures out of Their Normal Position in the Chest Radiograph (Cont’d) Causes • Pulled down by right middle lobe or right lower lobe atelectasis • Pushed down by right upper lobe neoplasm

43. Structure Left lung Abnormal Position Rightward shift Table 7-2Examples of Factors That Pull or Push Anatomic Structures out of Their Normal Position in the Chest Radiograph (Cont’d) Causes • Pulled right by right lung collapse, atelectasis, or fibrosis • Pushed right by left-sided tension pneumothorax or hemothorax

44. Other Radiologic Techniques • Computed tomography (CT) • CT scan • Position emission tomography (PET) • PET scan • Magnetic resonance imaging • Pulmonary angiography • Ventilation-perfusion scan • Fluoroscopy • Bronchography

45. Computed Tomography Computed tomography (CT) scanning provides a series of cross-sectional (transverse) pictures of the structures within the body at numerous levels.

46. Figure 7-9. The principle of spiral computed tomography. The patient moves into the scanner with the x-ray tube continuously rotating and the detectors acquiring information. The rapidity of data acquisition allows a complete examination of the throax to be performed in a single breath hold.

47. Normal CT Scan Lung Window Figure 7-10. Overview of normal lung window CT scan. The apex appears in the two views in the upper right corner of this figure; the diaphragm at the base of the lungs appears in the lower right hand view.

48. Example of Several Normal CT Scan Lung Window Slices

49. Normal CT Scan Lung Window A B Figure 7-10. B, The actual cross-sectional slice, or axial view of the chest. Figure 7-10. Close-up of a normal lung window CT scan. A, The portion of the chest the CT scan is taken.

50. Normal CT Scan Lung Window (Cont’d) Figure 7-10, cont.